Certain characteristics, as you mentioned, make evolutionary sense. Fins for water creatures. Legs for land creatures. Areodynamic wings for flying creatures. The article mentioned the very large eyes on the froglike alien resulting from the dark environment produced by K2-18b’s Red Dwarf sun.

K2-18b will certainly get much greater attention in the coming years. It is the JWST’s most significant discovery to date without a doubt. The planet deserves a better name at this point. What about Proteus, a sea god from greek mythology?

The middle pic just looks like ordinary Terran jellyfish.

The top picture looks like an earth frog head on a body equipped with shoulders, hips legs and arms jointed much like a primate, that is, ankles, wrists, knees, feet arranged pretty much like ours. The head is all wrong, though. It is too human in arrangement: two eyes above and on either side of a nose and a mouth (with an up-down jaw) below. It is hard to tell if that thing on the right side of its head is another eye or perhaps an ear, and if by symmetry there is another on the left side.

On our own world, there are many examples of distantly related organisms having similar body plans and organ structures. After all, some anatomical arrangements are very suitable for specific environments and are likely to appear over and over again in different planets. For example, plesiosaurs, fish and cetaceans have very similar shapes. On other worlds we may indeed find many creatures with body plans very similar to those found on earth. Still, too many of our aliens still are too humanoid in appearance. There is no reason intelligence must always arise in arboreal creatures adapted to savanna habitats.

What about intelligent termites? Or even cephalopods. The human arrangement is evolutionarily reasonable, but there is no reason it has to be that way everywhere, all the time.

Google some of the images depicting Larry Niven’s “Pierson’s Puppeteers”.

DailyMail.com took these findings to several of the most popular artificial intelligence (AI) chat programs, hoping that the vast sum of human knowledge in these computers could create an image of what these creatures might look like.

The image generators of ChatGPT, Grok, and DALL-E 3 didn’t disappoint, taking the atmospheric conditions of the exoplanet and producing their best possible guesses of how life would evolve on K2-18b.

The images AI predicted ranged from tiny swarms of jellyfish to frog-like creatures with eyes and limbs for walking.

Moreover, the image generators even predicted what these creatures might grow into after a few billion years of evolution.

Yeah, I know, far from conclusive analysis but still fun speculation.